Hold onto your green hats and lock down your certificates of green accomplishment: Joseph Lstiburek preached green-building heresy this week at the Green Building Summit — but it was a call for reform. The sacrilege: LEED isn't all it's cracked up to be, at least not in commercial construction, where the race for certification in Leadership in Energy & Environmental Design is attracting more runners every day.
Green with envyEverybody wants LEED certification for their new buildings and many developers are getting it, but the energy savings is probably nil, said Lstiburek, Ph.D., an engineer and principal of Boston-based Building Science Corp. He spoke Wednesday and Thursday at the summit, organized by the Oklahoma State Home Builders Association, the Association of Energy Engineers and third-party private consulting firm Guaranteed Watt Saver Systems. Green homebuilders' claims and work are tested every month when a homeowner pays a utility bill, Lstiburek said, so green residential construction mostly lives up to the green hype. Commercial and institutional buildings aren't held to such close, regular scrutiny, he said, pointing to a graph showing no statistical difference in energy efficiency and savings between a group of 150 LEED-certified commercial buildings and a group of 350 standard buildings. Lstiburek crunched data from the federal Commercial Buildings Energy Consumption Survey and the New Buildings Institute.
'Feel good' greenThe problem? LEED gives "green” points for construction factors and building features that have more to do with "feel good” aesthetics than energy conservation. "A bike rack? You get a green point for a bike rack?” he said incredulously, pointing out that as important as that might be to some people, it has nothing to do with building performance. Lstiburek said green building programs should focus 80 percent on energy efficiency and indoor air quality, 10 percent on water efficiency and 10 percent on materials. But no green certification programs come close, he said, not even LEED, the most widely known program. Lstiburek was right to point out the difference in green aesthetics and efficient building performance, said Kelly Parker, president of Guaranteed Watt Saver. "Some people lose sight of building science fundamentals when seeking green certification like LEED. They miss the point of how critical energy efficiency is and the significance of the building shell,” Parker said. "I think Joe's comments all come down to this: If you don't get the enclosure right or your building is an energy hog, you shouldn't really call it a green building. We guide project teams on this critical aspect so the green buildings in Oklahoma will not become bad examples. Green is a journey, and we just aren't there yet in commercial buildings.” Lstiburek, whose firm includes architects and who is married to an architect, called out architects for persisting with "colossally stupid” designs that offset advances in mechanical engineering that, at best, have most green buildings breaking even on efficiency.
Window problemsTake windows. Take them away. Architectural designs heavy on windows — more than 30 percent of a building's exterior — make most green efforts in a building moot, he said. Take "big holes” in buildings. Close them. Designs with "any hole you can crawl through” are designs with problems, he said. Take ventilation. LEED, Lstiburek said, wants buildings to be too ventilated, spelling out a requirement 30 percent greater than what the American Society of Heating, Refrigerating and Air-Conditioning Engineers recommends. Why? "Because of activists on the LEED committee that say everything in a building is unhealthy and sick” when it's not, he said.
Green takes timeTake time. Lstiburek said architects and engineers need to work closely together from the beginning of a design project, and drawings need to be especially detailed at points where walls meets floors and ceilings and around windows, where most problems with building efficiency lie — and where building plans are fuzziest. Lstiburek's remarks were provocative, especially considering the popularity of LEED. "I don't know if it's going to be received that well, but he made some points that needed to be made,” said Mike Means, executive vice president of the Oklahoma State Home Builders Association.